1. Field of the Invention
This invention relates to a deep-borehole drilling device and more particularly concerns such devices which include a drive unit coupled to drive a driven unit by drive transmission coupling means.
2. Description of the Prior Art
In deep-borehole drilling devices, mechanical drive transmission couplings are generally used to couple drive units to driven units as these couplings exhibit no temperature dependence, function with very little wear, and establish a direct physical connection between driving parts and driven parts. Such an arrangement is described in German Pat. No. 26 20 801.
The object underlying the invention is to provide a drilling tool with contact-free drive transmission coupling between the drive unit and the driven unit.